<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    let data = []
    for (let i = 0; i < 7; i++) {
        data.push({
            name: 'jack',
            id: i + 1,
            age: 20 + i
        })
    }

    let result = []


    for (let i = 0; i <= 7 / 3; i++) {
        result.push([])
    }

    let c = 0
    let q = 0
    data.forEach(((item, index) => { // 0 1 2      3 4 5

        result[c][q++] = item

        if ((index + 1) % 3 === 0) {
            c++
            q = 0
        }


    }))

    console.log(result)
</script>
</body>
</html>
